CN103820160A - Combustion chamber, coal water slurry gasification furnace with water wall and multiple opposite nozzles, and application of coal water slurry gasification furnace - Google Patents

Abstract

The invention relates to a combustion chamber and its water-cooled wall multi-nozzle opposed coal-water slurry gasification furnace and its application. The preheating nozzle chamber (3) on the top of the combustion chamber, the process nozzle chamber (4), and the gas slag outlet (5) located at the center of the lower end of the combustion chamber; the process nozzle chamber (4) is divided into 1~ 3 layers are arranged in the upper half space of the combustion chamber, and each layer is provided with 1 to 3 pairs of the process nozzle chambers (4); The standard metal pipe is coiled, and the inlet and outlet ends of the metal pipe are connected with the header. The combustion chamber designed by the present invention greatly expands the coal type adaptability range of the coal-water slurry gasification process, its components can be replaced or repaired separately, and the process nozzles installed in a plurality of process nozzle chambers 4 can work in whole or in part. The operating load range of the gasifier is greatly increased.

Description

Combustion chamber and its water wall multi-nozzle opposed coal-water slurry gasifier and its application

technical field

The invention relates to a combustion chamber and the structure of a coal-water slurry gasification furnace. A water-cooled wall is used as the internal part lining of the multi-nozzle opposed coal-water slurry gasification furnace.

Background technique

Entrained bed coal-water slurry gasification technology has been widely used in recent years. Among them, representative technologies include the coal-water slurry gasification technology of GE Company of the United States (formerly Texaco coal-water slurry gasification technology), and the multi-nozzle opposed coal gasification technology developed by East China University of Science and Technology (Chinese patent, patent number ZL98110616.1, ZL2005101114824.8, ZL01210097.8).

Traditional entrained bed coal-water slurry gasification technology generally uses refractory bricks and thermal insulation materials as the thermal insulation lining of the combustion chamber of the gasifier. The lining form of the combustion chamber of the gasifier has the functions of high temperature protection, heat storage and heat insulation.

The combustion chamber lining in the form of refractory bricks mainly has the following shortcomings:

1. There are restrictions on raw coal for coal-water slurry gasification. At present, traditional coal-water slurry gasifiers lined with refractory bricks generally use bituminous coal with a low ash melting temperature as the gasification coal raw material. The reason why coal with a lower ash melting temperature is used is that entrained bed gasifiers generally adopt the method of liquid slag removal. To turn coal ash into liquid slag, the temperature in the gasification zone needs to be higher than the ash melting temperature to remove the coal ash. Ashes melted. However, if the gasification temperature is too high, the corrosion of the refractory lining material will be greatly aggravated. In order to ensure a certain service life of the refractory lining material, coal with a lower ash melting temperature has to be used, which greatly limits the high ash that widely exists in China. Applicability of melting point coal in coal water slurry gasification process.

2. Refractory bricks need to be replaced regularly, which leads to high costs and serious environmental problems. Even if suitable coal for coal-water slurry gasification (referring to low melting point of ash), the refractory brick lining, especially the innermost high-temperature resistant refractory brick, will be damaged after a period of use due to the erosion and erosion of high-temperature gas slag. , it is necessary to replace the partial or overall refractory brick lining. On the one hand, this increases the operating cost of the enterprise. In addition, since the current refractory brick materials basically use chromium as the main raw material, the preparation and melting of chromium brings serious environmental problems.

Refractory bricks need to be preheated, which increases operating costs and reduces equipment availability.

Contents of the invention

The main purpose of the present invention is to provide a kind of technology that uses water wall as the combustion chamber lining of coal-water slurry gasifier to solve the disadvantages of the traditional combustion chamber of coal-water slurry gasifier that uses refractory bricks as the lining.

A combustion chamber, which includes a metal furnace shell 1, a coiled water-cooled wall inner part 2, a preheating nozzle chamber 3 arranged on the top of the combustion chamber, a process nozzle chamber 4, and a center of the lower end of the combustion chamber Part of the air slag outlet 5;

The process nozzle chamber 4 is divided into 1 to 3 layers in the horizontal direction (the process nozzle chamber 4 of each layer is located on the same horizontal plane) and is arranged in the upper half space of the combustion chamber, and each layer is provided with 1 to 3 pairs of the Process nozzle chambers 4, and the process nozzle chambers 4 of each layer are evenly arranged in the circumferential direction of the gasifier;

The coil-type water-cooled wall internals 2 are coiled from 2 to 10 metal tubes of the same specification, and the inlet and outlet ends of the metal tubes are connected to the header; the vertical coil-type water-cooled wall internals 2 The axis coincides with the vertical axis of the metal furnace shell 1;

The gas slag outlet 5 is coaxial with the combustion chamber in the vertical direction, and the gas slag outlet 5 is formed by coiling 1 to 5 metal pipes.

The preheating nozzle chamber 3 coincides with the vertical axis of the metal furnace shell 1, and the preheating nozzle chamber 3 is formed by coiling 1 to 5 metal pipes.

There is a gap filled with elastic light refractory material between the preheating nozzle chamber 3 and the coiled water-cooled wall inner part 2 .

There is a gap filled with elastic light refractory material between the gas slag outlet 5 and the coiled water-cooled wall inner part 2 .

The process nozzle chamber 4 includes the furnace shell horizontal hole 6 of the metal furnace shell 1 and the water-cooled wall horizontal hole 7 of the coiled water-cooled wall internal part 2, and the furnace shell horizontal hole 6 is horizontal to the water-cooled wall The holes 7 are connected to each other by bellows 9, and the horizontal central axes of the horizontal holes 6 of the furnace shell and the horizontal holes 7 of the water cooling wall are parallel to each other.

A water-cooled wall multi-nozzle opposed coal-water slurry gasifier has any one of the above-mentioned combustion chambers.

The application of the above-mentioned multi-nozzle opposed coal-water slurry gasifier with a water wall is specifically: using the gasifier for the gasification of the coal-water slurry feed entrained flow bed, including the following steps: The process nozzle sprays coal-water slurry gasification raw materials and oxygen into the combustion chamber for gasification reaction, and the generated high-temperature gas and high-temperature slag flow downward and are discharged from the combustion chamber through the gas slag outlet 5 .

In the initial stage of the gasification reaction, gaseous or liquid fuel and oxidant (for example, air, etc.) are sprayed into the preheating nozzle installed in the preheating nozzle chamber 3 to carry out the combustion reaction, and the coiled water cooling The wall internals 2 are preheated; when the coil-type water-cooled wall internals 2 are preheated to a specified temperature, the coal-water slurry gasification raw material and the oxygen are passed through the process nozzle installed in the process nozzle chamber 4 spray into the combustion chamber and be ignited by the flame of the preheating nozzle; after the flame of the process nozzle is stable, extinguish the flame of the preheating nozzle.

After all or part of the process nozzle has established a stable flame with the coal-water slurry gasification raw material and oxygen, and extinguished the flame of the preheating nozzle, continue to feed nitrogen, carbon dioxide, steam or Mixed gas, or continue to feed new coal-water slurry gasification raw materials and oxygen as gasification feed, or feed mixed gas generated by gasification reaction;

Wherein, when part of the process nozzle is injected into the coal-water slurry gasification raw material and oxygen for gasification reaction, other parts of the process nozzle are injected with a small amount of single or mixed gases in nitrogen, carbon dioxide, and water vapor, To protect the process nozzle from being damaged by the high temperature formed by the gasification reaction.

Compared with the traditional coal-water slurry gasification technology lined with refractory bricks, the present invention has the following significant advantages:

1. The water-cooled wall is used as the internal structure of the coal-water slurry gasifier, and the characteristics of "resisting slag with slag" of the water-cooled wall can be used to gasify coal with a high ash melting temperature, which greatly expands the coal type application range of the water-coal gasification process.

2. The coil-type water-cooled wall 2 is used as the main internal structure of the combustion chamber of the gasifier. There is no gap between the top preheating nozzle chamber 3, the side-mounted process nozzle chamber 4 and the lower gas slag outlet 5 and the coil-type water-cooled wall. The connection is directly fixed, and the gap is filled with elastic lightweight refractory material. In this way, the latter three can be separated from the coil water cooling wall, and can be replaced or repaired separately. On the one hand, it improves the reliability of related components, and on the other hand, it also minimizes the failure rate and maintenance workload of the main body of the water-cooled wall.

3. Use the preheating nozzle installed in the top preheating nozzle chamber 3 to preheat the inside of the combustion chamber of the gasifier, and provide a stable flame to ignite the coal slurry and oxygen injected by the process nozzle installed in the process nozzle chamber 4, There is no need to switch the pre-combustion flame and the coal slurry oxygen process feed in the same nozzle, which makes the start-up process of the coal-water slurry gasifier simple and reliable.

4. The process nozzles installed in multiple process nozzle chambers 4 can work with all or part of the process nozzles, which greatly increases the operating load range of the gasifier.

Description of drawings

Fig. 1 is the structural representation of the combustion chamber in the multi-nozzle opposed type coal-water slurry gasifier with water wall;

Fig. 2 is a structural schematic diagram of the inner part of the coiled water-cooled wall.

Symbol Description:

1 Metal furnace shell; 2 Coil water-cooled wall internals; 3 Preheating nozzle chamber; 4 Process nozzle chamber;

5 gas slag outlet; 6 horizontal hole in the furnace shell; 7 horizontal hole in the water wall, 8 process nozzle;

9 bellows; 10 positioning block; 11 water wall coil inlet pipe;

12 water wall coil outlet pipe; 13 preheating nozzle; 14 elastic light refractory material;

15 preheating nozzle opening; 16 air slag outlet opening.

Detailed ways

The content of the present invention will be further illustrated below in conjunction with examples, but these examples do not limit the protection scope of the present invention.

Example 1

As shown in Figure 1, the combustion chamber in the water-wall multi-nozzle opposed coal-water slurry gasifier has a metal furnace shell 1, the main body of which is a cylindrical structure. The upper part of the metal furnace shell 1 is a spherical head and the lower part is conical. structure. The lower part of the metal furnace shell 1 can be connected with a gasification washing cooling device or heat recovery device with the same diameter or different diameter. The center of the spherical head, the straight section of the cylinder and the lower end of the conical lower part are provided with circular openings, which are respectively used as installation positions for the preheating nozzle 13, the process nozzle 8 and the gas slag outlet 5.

The combustion chamber also has a coil-type water-cooled wall internal part 2, a preheating nozzle chamber 3 located on the top of the combustion chamber, a process nozzle chamber 4, and an air slag outlet 5 located at the center of the lower end of the combustion chamber.

In order to ensure a certain distance between the coiled water-cooled wall inner part 2 and the metal furnace shell 1 during thermal expansion and contraction, a positioning block 10 is provided.

The process nozzle chamber 4 is arranged in the upper half space of the combustion chamber in 1 to 3 layers in the horizontal direction, and each layer is provided with 1 to 3 pairs of process nozzle chambers 4, that is, the process nozzle chambers 4 on the same layer are located on the same horizontal plane, and The process nozzle chambers 4 on the same layer are evenly arranged in the circumferential direction of the gasifier;

The gas slag outlet 5 is coaxial with the combustion chamber in the vertical direction, and is formed by coiling 1 to 5 metal pipes.

The preheating nozzle chamber 3 coincides with the vertical axis of the metal furnace shell 1 and is formed by coiling 1 to 5 metal tubes. The preheating nozzle chamber 3 is arranged at the center of the top of the combustion chamber, and is formed by an independent and detachable cylindrical structure coiled by a metal tube and coaxially installed in the open space at the top of the coiled water-cooled wall internal part 2 . Adopting the structure of the preheating nozzle chamber 3 designed by the present invention, the preheating nozzle chamber can be replaced and repaired independently without affecting the main water wall coil.

There are gaps (3-200 mm) filled with elastic light refractory material 14 between the preheating nozzle chamber 3 and the coiled water-cooled wall inner part 2 and between the air slag outlet 5 and the coiled water-cooled wall inner part 2 .

The process nozzle chamber 4 includes the furnace shell horizontal hole 6 of the metal furnace shell 1 and the water-cooled wall horizontal hole 7 of the coil-type water-cooled wall inner part 2, and the furnace shell horizontal hole 6 and the water-cooled wall horizontal hole 7 are connected to each other by a bellows 9 , the horizontal central axes of the furnace shell horizontal hole 6 and the water wall horizontal hole 7 are parallel to each other.

The process nozzle chamber 4 is designed on the side of the straight section of the combustion chamber. As mentioned above, there is an open space at the position corresponding to the metal furnace shell 1 and the water-cooled wall coil 2, and an independent detachable nozzle is formed in the open space. A cylindrical structure formed of coiled metal tubes, the cylindrical structure is an indoor cylinder of the process nozzle parallel to the central axis of the opening of the water wall coil 2 . However, when installed in a cold state, the central axis of the inner cylinder of the process nozzle is slightly lower than the central axis of the opening of the water-cooled wall coil 2. The shaft and the central axis of the inner cylinder are as coaxial as possible. The inner tube of the process nozzle is fixed on the side close to the metal furnace shell 1 with the bellows 9 and a short connection pipe with the same diameter, and the short connection pipe is fixed on the metal furnace shell 1 by welding. The bellows 9 can eliminate the stress between the inner cylinder of the process nozzle and its fixed end caused by thermal expansion and contraction. A certain gap (3-200mm) is reserved between the inner cylinder of the process nozzle and the main water-cooled wall coil, and the gap space is filled with elastic light-weight refractory materials. The inner barrel of the process nozzle can be disassembled and repaired independently without affecting the main water wall coil.

The air slag outlet 5 is located at the center of the cone bottom at the lower part of the coil-type water-cooled wall inner part 2 . The air slag outlet 5 is formed by an independent and detachable cylindrical structure coiled by a metal tube to form the air slag outlet inner cylinder, and the opening space between the air slag outlet inner cylinder and the air slag outlet 5 at the lower part of the coiled water wall internal part 2 Coaxial, and have a certain gap (3 ~ 200mm), the gap space is filled with elastic light refractory material. The air slag outlet inner cylinder can be disassembled and repaired independently without affecting the inner part 2 of the coiled water cooling wall.

As shown in Fig. 2, the coil type water-cooled wall inner part has a main body of a coil type structure. The so-called coiled tube type is formed by a number of metal tubes (2 to 10 in the present invention, preferably 3 to 5) that are spirally coiled in parallel, and the preheating nozzle chamber 3, the process nozzle chamber 4 and the gas nozzle chamber 4 are reserved at corresponding positions. The opening space of the slag outlet 5 (preheating nozzle opening 15 and gas slag outlet opening 16 are shown in the figure). In order to protect the metal coil, a layer of 0.5-200mm thick heat-insulating refractory material, such as silicon carbide, can be laid on the surface of the metal coil near the furnace. When the coal-water slurry gasification reaction process occurs in the combustion chamber of the gasifier, the ash in the coal melts at high temperature, and part of the ash adheres to the surface of the water wall and is cooled and solidified, thereby forming a dynamic protective layer to protect the water cooling wall. The wall coil is not ablated by high temperature. The thickness of this dynamic slag layer changes with the coal type and gasification temperature, but in general, from the wall of the water-cooled wall coil to the furnace, the order is: solid slag layer, softened slag layer and mobile slag layer.

The inlet and outlet ends of parallel helically coiled metal pipes are connected to the header; the vertical axis of the coiled water-cooled wall internal part 2 coincides with the vertical axis of the metal furnace shell 1, and has a water-cooled wall coil inlet pipe 11 and a water-cooled Wall coil pipe outlet pipe 12.

The combustion chamber of the gasification furnace designed according to the invention has the characteristics of fast and stable ignition at start-up. Through the preheating nozzle in the preheating nozzle chamber on the top, diesel, natural gas, liquefied petroleum gas, factory bleed gas or other gas and liquid fuels are used for combustion reaction with air. First, the main water-cooled wall coil is preheated, and then The coal-water slurry and oxygen are sprayed through the process nozzle installed in the process nozzle chamber, ignited by the flame formed by the preheating nozzle, and the gasification combustion reaction is carried out. The flame of the preheating nozzle can be maintained for a period of time. After the flame of the process nozzle is completely stable, off. After the flame is extinguished, the preheating nozzle can inject a small amount of nitrogen, carbon dioxide or steam to protect itself. Since the combustion chamber of the gasification furnace designed by the present invention is provided with a plurality of process nozzle chambers and process nozzles, when the system is feeding materials, one pair of nozzles can feed materials, or two pairs of nozzles can feed materials at the same time.

The combustion chamber of the gasification furnace designed according to the invention also has the characteristics of wide load range and flexible adjustment means. Due to the setting of multiple process nozzle chambers and their process nozzles, the combustion chamber of the gasifier can use all process nozzles to work at the same load, or some process nozzles can work while other process nozzles are protected with a small amount of nitrogen, carbon dioxide or steam The gasifier can be stopped working under different conditions, or the process nozzles in different positions work according to different loads. Through these flexible adjustment methods, the overall gasifier can work within a very large load range.

Claims (10)

1. a combustion chamber, it is characterized in that, described combustion chamber comprises metal furnace shell (1), coil tube type water wall internals (2), is located at the preheating nozzle box (3) of described top of combustion chamber, technique nozzle box (4), be positioned at the gas slag outlet (5) in centre, lower end, described combustion chamber;

Described technique nozzle box (4) divides 1～3 layer of upper part space that is arranged on described combustion chamber by horizontal direction, every one deck is provided with 1～3 pair of described technique nozzle box (4), and the described technique nozzle box (4) of every one deck is evenly arranged on the circumferential direction of described vapourizing furnace;

Described coil tube type water wall internals (2) are coiled to form by the metal tube of 2～10 same sizes, and the turnover end of described metal tube is connected with header; The vertical axis of described coil tube type water wall internals (2) overlaps with the vertical axis of described metal furnace shell (1).

2. combustion chamber according to claim 1, is characterized in that, described gas slag outlet (5) is coaxial with described combustion chamber in the vertical direction, and described gas slag outlet (5) is coiled to form by 1～5 metal tube.

3. combustion chamber according to claim 1, is characterized in that, described preheating nozzle box (3) overlaps with the vertical axis of described metal furnace shell (1), and described preheating nozzle box (3) is coiled to form by 1～5 metal tube.

4. combustion chamber according to claim 1, is characterized in that, has the gap of filling with elastomeric light fire resistant materials between described preheating nozzle box (3) and described coil tube type water wall internals (2).

5. combustion chamber according to claim 1, is characterized in that, has the gap of filling with elastomeric light fire resistant materials between described gas slag outlet (5) and described coil tube type water wall internals (2).

6. combustion chamber according to claim 1, it is characterized in that, described technique nozzle box (4) comprises the furnace shell lateral aperture (6) of described metal furnace shell (1) and the water wall lateral aperture (7) of described coil tube type water wall internals (2), between described furnace shell lateral aperture (6) and described water wall lateral aperture (7), connect mutually by corrugated tube (9), the horizontal center line axis of described furnace shell lateral aperture (6), water wall lateral aperture (7) is parallel to each other.

7. a water wall multiple-nozzle contraposition type coal water slurry gasification stove, is characterized in that, the described gasification stove arbitrary described combustion chamber of requirement 1 to 6 of having the right.

8. the application of water wall multiple-nozzle contraposition type coal water slurry gasification stove claimed in claim 7, it is characterized in that, gasification by described vapourizing furnace for coal water slurry feeding gas fluidized bed, comprise the steps: that coal water slurry gasification raw material and oxygen are sprayed into described combustion chamber by the technique nozzle by being installed on technique nozzle box (4), carry out gasification reaction, the high-temperature gas and the high-temperature slag that generate flow downward, and discharge described combustion chamber through described gas slag outlet (5).

9. application according to claim 8, it is characterized in that, at the initial stage of described gasification reaction, spray into gaseous state or liquid fuel and oxygenant by the pre-hot nozzle of installing in described preheating nozzle box (3), carry out combustion reactions, make described coil tube type water wall internals (2) carry out preheating; In the time that described coil tube type water wall internals (2) are preheating to assigned temperature, more described coal water slurry gasification raw material and described oxygen are sprayed into described combustion chamber the flame ignition by described pre-hot nozzle by being installed on the technique nozzle of technique nozzle box (4); After the flame stabilization of described technique nozzle, extinguish the flame of described pre-hot nozzle.

10. application according to claim 9, it is characterized in that, set up in whole or in part and the stationary flame of described coal water slurry gasification raw material and oxygen at described technique nozzle, and extinguish after the flame of described pre-hot nozzle, continue to pass into the single or mixed gas in nitrogen, carbonic acid gas, water vapor, or continue to pass into new coal water slurry gasification raw material and oxygen as gasification feed, or pass into the gas mixture that gasification reaction produces;

Wherein, in the time that the part of described technique nozzle sprays into described coal water slurry gasification raw material and oxygen and carries out gasification reaction, other parts of described technique nozzle spray into the single or mixed gas in a small amount of nitrogen, carbonic acid gas, water vapor.

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